It is common in a classroom or lecture hall for the teacher or lecturer to use visual aids, such as photographic slides and overhead projector transparencies or overlays. Normally, the slide projector or overhead projector projects the image onto a screen positioned behind the speaker near the front wall of the room. This position of the screen allows the audience to view the image without changing their position. However, if the teacher or lecturer wishes to also view the image projected on the screen, he/she must turn his/her back to the audience, thereby losing the normal face-to-face orientation with the class. This loss of visual contact with the audience diminishes the speaker's effectiveness. Also, it is usually necessary to dim the lights in the room when a slide projector or overhead projector is being used.
All of these defects are magnified greatly when the same lecture format is used in the production of educational television or satellite telecourses. Washed-out projections, lighting contrast rations beyond the capability of the television system to produce, difficulty in maintaining the proper 4.times.5 size ratio of the picture format used in the television system, and turning of the lecturer's back to the studio cameras are among the reasons lectures are hard for a production staff to deal with.
These problems can be avoided, but only at the expense of many hours of pre-production time spent turning all written materials into television graphics. Valuable instructor time is also needed in getting the lecture materials in a more usable form. In addition, to effectively use television graphics and deal with appearing on camera, the instructor must be comfortable with television performance. As with any performing art, it takes most people a long time to become sufficiently accomplished to project themselves to their audience.
Therefore, the primary objective of the present invention is to allow the use of a routine classroom lecture in a television studio situation.
Another objective of the present invention is the provision of an improved projection system for projecting an image from a lecturer to an audience for viewing by the lecturer and by the audience in classes outside the television studio.
Another objective of the present invention is the provision of a means and method of projecting an image for viewing by a speaker and an audience while maintaining the face-to-face orientation between the speaker, the audience, and the television studio cameras.
Still a further objective of the present invention is the provision of a method and means of projecting an image for viewing by a audience in the normal lighting of the room.
A further objective of the present invention is the provision of an improved projection system which is easy to operate and which maximizes the effect of visual aids used by a lecturer or teacher.